Multifunction Transformer With Adjustable Magnetic Stage Based on Nanocomposite Semihard Magnets

In order to improve the efficiency, reliability of power supply, and to give overall consideration to the power transformation and power quality control, a brand-new multifunction transformer with intrinsic adjustable magnetic state is put forward based on semihard magnets NdFeB in this paper. First, according to the formation mechanism of dc bias and the regulation means of inductance value, the peculiar core structure of a single-phase transformer is designed so as to realize the flux adjustment of transformer core under different magnetic states. Second, taking advantage of the magnetic conductive and excitation characteristics of NdFeB, the magnetic state conversion of electromagnet core between several kinds of working conditions can be achieved, such as voltage transformation, adjustable inductance, and dc bias compensation. Finally, two 10 kVA transformers with adjustable magnetic state are manufactured. The experiments of dc bias compensation and inductance regulation are carried out, which validates the feasibility and correctness of the design scheme.